Social organization and behaviour of the Grey-crowned Babbler Pomatostomus temporalis

Abstract

The social system of wild and captive Grey-crowned Babblers Pomatostomus temporalis was studied in south-eastern Queensland. Three classes of age were distinguished on colour of iris and a fourth by difference in plumage. Adult birds could be sexed by length of bill. The ratio of males to females in a population did not differ significantly from unity. The species occurred in sedentary territorial groups, each of which usually contained a single breeding pair and a number of non-breeding birds. Non-breeding members were of all ages and mostly the offspring of previous broods of the breeding pair. Groups moved as closely knit units and much behaviour was directed towards cohesion of the group. Patterns of behaviour and calls are described. Groups were strongly territorial and spent much time in disputes with neighbouring groups. In general, size of home range did not directly correlate with size of group. All members of a group co-operate in building and care of the young but only the breeding female incubates and broods. The degree of participation of an in- dividual in visiting nests and feeding young usually corresponds with its age and status within the group.